package com.brooks.demo;

import java.util.concurrent.CountDownLatch;

/**
 * CountDownLatch 公平锁
 *
 * @Author mihutu
 * @Date 2020/10/18 21:54
 * @Version 1.0
 */
public class DemoCountDownLatch {

    private static void useCountDownLatch(){
        Thread[] threads = new Thread[100];
        CountDownLatch latch = new CountDownLatch(threads.length);
        for (int i=0;i<threads.length;i++){
            threads[i] = new Thread(()->{
                int result = 0;
                for (int j=0;j<10000;j++){
                    result+=j;
                }
                latch.countDown();
            });
        }
        for (int i=0;i<threads.length;i++){
           threads[i].start();
        }
        try {
            latch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("end latch");
    }

    private static void useJoin(){
        Thread[] threads = new Thread[100];
        for (int i=0;i<threads.length;i++){
            threads[i] = new Thread(()->{
                int result = 0;
                for (int j=0;j<10000;j++){
                    result+=j;
                }
            });
        }
        for (int i=0;i<threads.length;i++){
           threads[i].start();
        }
        for (int i=0;i<threads.length;i++){
            try {
                threads[i].join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("end join");
    }

    public static void main(String[] args) {
        useCountDownLatch();
        useJoin();
    }
}